SBAS511E july   2010  – july 2023 ADS1013-Q1 , ADS1014-Q1 , ADS1015-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Revision History
  6.   Device Comparison Table
  7. 5 Pin Configuration and Functions
  8. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Timing Requirements: I2C
    7. 6.7 Timing Diagram
    8. 6.8 Typical Characteristics
  9. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagrams
    3. 7.3 Feature Description
      1. 7.3.1 Multiplexer
      2. 7.3.2 Analog Inputs
      3. 7.3.3 Full-Scale Range (FSR) and LSB Size
      4. 7.3.4 Voltage Reference
      5. 7.3.5 Oscillator
      6. 7.3.6 Output Data Rate and Conversion Time
      7. 7.3.7 Digital Comparator (ADS1014-Q1 and ADS1015-Q1 Only)
      8. 7.3.8 Conversion Ready Pin (ADS1014-Q1 and ADS1015-Q1 Only)
      9. 7.3.9 SMbus Alert Response
    4. 7.4 Device Functional Modes
      1. 7.4.1 Reset and Power-Up
      2. 7.4.2 Operating Modes
        1. 7.4.2.1 Single-Shot Mode
        2. 7.4.2.2 Continuous-Conversion Mode
      3. 7.4.3 Duty Cycling For Low Power
    5. 7.5 Programming
      1. 7.5.1 I2C Interface
        1. 7.5.1.1 I2C Address Selection
        2. 7.5.1.2 I2C General Call
        3. 7.5.1.3 I2C Speed Modes
      2. 7.5.2 Target Mode Operations
        1. 7.5.2.1 Receive Mode
        2. 7.5.2.2 Transmit Mode
      3. 7.5.3 Writing To and Reading From the Registers
      4. 7.5.4 Data Format
    6. 7.6 Register Map
      1. 7.6.1 Address Pointer Register (address = N/A) [reset = N/A]
      2. 7.6.2 Conversion Register (P[1:0] = 00b) [reset = 0000h]
      3. 7.6.3 Config Register (P[1:0] = 01b) [reset = 8583h]
      4. 7.6.4 Lo_thresh (P[1:0] = 10b) [reset = 8000h] and Hi_thresh (P[1:0] = 11b) [reset = 7FFFh] Registers
  10. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Basic Connections
      2. 8.1.2 Single-Ended Inputs
      3. 8.1.3 Input Protection
      4. 8.1.4 Unused Inputs and Outputs
      5. 8.1.5 Analog Input Filtering
      6. 8.1.6 Connecting Multiple Devices
      7. 8.1.7 Quick-Start Guide
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Shunt Resistor Considerations
        2. 8.2.2.2 Operational Amplifier Considerations
        3. 8.2.2.3 ADC Input Common-Mode Considerations
        4. 8.2.2.4 Resistor (R1, R2, R3, R4) Considerations
        5. 8.2.2.5 Noise and Input Impedance Considerations
        6. 8.2.2.6 First-Order RC Filter Considerations
        7. 8.2.2.7 Circuit Implementation
        8. 8.2.2.8 Results Summary
      3. 8.2.3 Application Curves
    3. 8.3 Power Supply Recommendations
      1. 8.3.1 Power-Supply Sequencing
      2. 8.3.2 Power-Supply Decoupling
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  11. 9 Device and Documentation Support
    1. 9.1 Documentation Support
      1. 9.1.1 Related Documentation
    2. 9.2 Receiving Notification of Documentation Updates
    3. 9.3 Support Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  12. 10Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

8.2.2.4 Resistor (R1, R2, R3, R4) Considerations

Proper selection of resistors R1, R2, R3, and R4 is critical for meeting the overall accuracy requirements.

Using Equation 6, the offset term, VOUT-OS, and the gain term, AOUT, of the differential ADC input are represented by Equation 9 and Equation 10 respectively. The error contributions from the first-order RC filters are ignored.

Equation 9. VOUT-OS = VCM · (R2 / R1 - R3 / R4) / (1 + R3 / R4)
Equation 10. AOUT = (1 + R2 / R1) / (1 + R4 / R3)

The tolerance, drift, and linearity performance of these resistors is critical to meeting the overall accuracy requirements. In Equation 9, if R1 = R3 and R2 = R4, VOUT-OS = 0 V and therefore, the common-mode voltage, VCM, only contributes to level-shift VSHUNT and does not introduce any error at the differential ADC inputs. High-precision resistors provide better common-mode rejection from VCM.